Antibiotics and opioids are the top therapeutic categories prescribed by dentists. Interestingly, factors associ- ated with prescribing behaviors of these medication classes are similar. Our preliminary data on dental pre- scribing demonstrates that 1) high prescribers of opioids are also high prescribers of antibiotics and 2) over- prescribing of antibiotics and opioids is common. However, there is a knowledge gap in our understanding of medication prescribing and overprescribing (for inappropriate indications and/or excessive quantity/potency/ duration) by dentists. This gap is significant because dentists prescribe 1 out of every 10 prescriptions (Rx) for both antibiotics and opioids in the US. Inappropriate and appropriate use of antibiotic and opioids are a risk to patient safety, including: bacterial resistance, C. difficile infection (CDI), opioid overdose, drug de- pendence and diversion. Opioid overprescribing is concerning because substance users commonly seek opioids from dentists, dentists infrequently use prescription drug monitoring programs (PDMP) and fatalities secondary to opioid use have been linked to dental prescribing. Use of antibiotics for infection prophylaxis prior to dental procedures has been associated with CDI. Guidelines for infective endocarditis and prosthetic joint infection prophylaxis during dental procedures were recently updated, significantly reducing the number of patients requiring antibiotic prophylaxis. However, despite infection prophylaxis being the primary indica- tion for antibiotics prescribed by dentists, our national data shows only a small (0.7%) decrease in overall dental antibiotic prescribing. Although efforts are increasing to curtail overuse of these medication classes, most interventions are focused on medical providers. Guided by preliminary data, we will be pursuing 3 spe- cific aims: 1) Assess dental prescribing of antibiotics and opioid medications and identify characteristics as- sociated with high rates of inappropriate prescribing; 2) Describe dentists' attitudes towards prescribing anti- biotics and opioids among those with high and low prescribing patterns in high and low prescribing facilities; and 3) Develop a pilot implementation study to improve dental prescribing. The proposed study is aligned with the research priority areas of HSR&D (healthcare equity-vulnerable populations; implementation sci- ence-provider behavior; and patient-centered care-opioid use) and 2 White House National Action Plans fo- cused on antibiotic resistance and adverse drug events. The goals of this collaborative project also align with the priorities of our operational partners: VA Dental Services, PBM MedSafe, and the Antimicrobial Steward- ship Task Force. We propose to conduct a mixed-methods study to assess antibiotic and opioid dental pre- scribing based on American Dental Association recommendations and identify factors related to prescribing. We will triangulate results from administrative data and interviews with `high' and `low'-prescribing dentists at `high' and `low'-prescribing facilities. The expected outcomes of this study include providing baseline data on the extent of antibiotic and opioid overprescribing by dentists, identification of barriers and facilitators to im- proving prescribing of antibiotics and opioids and development of a pilot implementation project to improve the quality of dental care. Additionally, VA provides a unique opportunity to study dental prescribing because ICD9/10 coding by private sector dentists is rare. Thus, the impact of our results are likely to be far-reaching. This research is innovative in that it will be the first study, to our knowledge, utilizing national VA databases to answer research questions on dental prescribing of antibiotics and opioids. The goal of the proposed pro- ject is to develop actionable findings for decision makers that can be implemented to improve evidence- based prescribing of antibiotics and opioids by dentists. Our long-term goal is to improve Veteran dental care by implementing interventions that will increase prudent antimicrobial use, decrease opioid overprescribing and decrease serious adverse events. Simultaneously intervening on the misuse of antibiotics and opioids may more efficiently improve evidenced-based care delivered by dentists.